Effective interface of a composite membrane serving as an ideally ultrathin barrier layer

A novel idea relating to the selective barrier layer of a composite membrane is described. The effective interface of the composite membrane could act as a barrier layer which could be controlled to an ideally ultrathin thickness. A new type of polyamide composite membrane was prepared according to this idea, which possessed permeability and chemical resistance more than one magnitude greater than those of ordinary polyamide composite membranes. Copyright (C) 1996 Elsevier Science Ltd.

Study on the Films Forming Process of Nanosized SnO2 Colloid Particles at the Gas-Liquid Interface

The hydrosol of SnO2 nanoparticles are prepared by the method of colloid chemistry. The free piling up process of nanosized SnO2 colloid particles are investigated at the gas-liquid interface by LB and Brewster Angle Microscopy techniques. The result indicates that solid state monolayer and multilayer of SnO2 nanoparticles can be formed at the gas-liquid interface only by aging the sol in air or compressing it without amphiphiles surfactant.

EFFECTS OF CRYSTALLIZATION RATES ON INTERFACE LAYER THICKNESS OF EPITAXIAL HDPE ON ORIENTED IPP

The effect of crystallization rate on the epitaxial interface layer thickness of high-density polyethylene (HDPE) in the epitaxial system with oriented isotactic polypropylene (iPP) has been investigated by electron microscopy. The results of bright-field

SMALL-ANGLE X-RAY-SCATTERING STUDY ON THE INTERFACE IN BLOCK-COPOLYMERS WITH FRACTAL PROPERTIES

The interface thickness in two triblock copolymers were determined using small-angle x-ray scattering in the context of the theory proposed by Ruland. The thickness was found to be nonexistent for the samples at three different temperatures. By viewing th

ION TRANSFER OF CHROMAZUROL-S ACROSS THE LIQUID-LIQUID INTERFACE

The ion transfer of 0hromazural S (CAS) across ~he in%erface of W/NB and W/l, 2- ])CE was sgadied by oyclie vol~amme~ry and ehronopoten~iome~ry wibh linear current scanning. The $ransfer mechanism of GAS was proposed in terms of lis eleo~roohemic~l behavior and equilibria of diasocia~ion. The experimental da~a obtained for half-wave po~eniial AoWT~/~ and pH in W phase are in agreemen~ wi~h ~he ~heoretieal equation based on ~he mechanism proposal. The siandard po~engial differences AoWT~ and standa...

STUDY ON DYE TRANSFER ACROSS THE LIQUID-LIQUID INTERFACE

I. INTRODUCTIONStudies on the electrochemical phenomena at the liquid-liquid interface are a developing area in electrochemistry and electroanalytical chemistry. The exploration for new ion transfer systems is very important in the development of this area. Dyes are a large group of reagents used widely in analytical chemistry. But no paper deals with the tran,fer processes of dyes at the liquid-liquid (L/L) interface so far.

Dissolved inorganic carbon and CO2 fluxes across Jiaozhou Bay air-water interface

On the basis of data collected in the Jiaozhou Bay in June and July 2003, the DIC distribution in seawater is studied, and an average air-sea flux of CO2 is estimated. The results show that the content of DIC inside the bay is markedly higher than outside the bay in June, but the content of DIC outside the bay is markedly higher than inside the bay in July. The trend of DIC distribution inside the bay is similar, viz. the content is the maximum in the northeast, then decreases gradually toward the west, and the content is the minimum in the west. The total trend of vertical distribution is to increase gradually from surface to bottom. This characteristic of DIC distribution is determined by Jiaozhou Bay hydrology and there is a close relation between DIC and particulate N,P. Average CO2 flux across the air-sea interface is 0.55 mol/(m(2.)a) in June and 0.72 mol/(m(2.)a) in July. Jiaozhou Bay is considered as a net annual source for atmospheric CO2 in June and July, and the total CO2 flux from seawater into atmosphere is about 740 t in June and 969 t in July.

Dissolved oxygen and O-2 flux across the water-air interface of the Changjiang Estuary in May 2003

The field observation of this study was carried out in the Changjiang Estuary from May 19 to 26,2003, just a few days before the Three Gorges Dam began to store water. A total of 29 stations, including 2 anchor stations, were distributed through almost the whole salinity gradient Based on the data gained from these stations, the biogeochemical characteristics of dissolved oxygen (DO) were examined. Spatial distribution of DO concentrations showed the pattern that it increased in a downriver direction. DO concentration generally varied within a narrow range of 733-8.10 mg l(-1) in the freshwater region and the west part of the mixed water region, and after that it increased rapidly. In vertical direction, the differences in DO concentrations between surface and 2 m above the bottom were big at the stations with water depths exceeding 20 m; DO concentration up to 14.88 mg l(-1) was recorded at the sea surface, while at 2 m above the bottom its concentration was only about 4 mg l(-1). The fluctuation in DO concentrations was small during a period of 48 h in the mixed water region and 2 m above the bottom of the seawater region; while it was large during the same period in the seawater region for surface and 5 m below the surface layer, and a maximum variation from 8.77 to 12.66 mg l(-1) in 4 h was recorded. Oxygen fluxes also showed a marked spatio-temporal variation. As a whole, the freshwater region and mixed water region were an oxygen sink while the seawater region was a source. Relationships between dissolved oxygen and some biogeochemical parameters which could markedly influence its spatio-temporal distribution were discussed in this paper. (C) 2008 Elsevier B.V. All rights reserved.

pCO(2) and carbon fluxes across sea-air interface in the Changjiang Estuary and Hangzhou Bay

Partial pressure of CO2 (pCO(2)) was investigated in the Changjiang (Yangtze River) Estuary, Hangzhou Bay and their adjacent areas during a cruise in August 2004, China. The data show that pCO(2) in surface waters of the studied area was higher than that in the atmosphere with only exception of a patch east of Zhoushan Archipelago. The pCO(2) varied from 168 to 2 264 mu atm, which fell in the low range compared with those of other estuaries in the world. The calculated sea-air CO2 fluxes decreased offshore and varied from -10.0 to 88.1 mmol m(-2) d(-1) in average of 24.4 +/- 16.5 mmol m(-2) d(-1). Although the area studied was estimated only 2 x 10(4) km(2), it emitted (5.9 +/- 4.0) x 10(3) tons of carbon to the atmosphere every day. The estuaries and their plumes must be further studied for better understanding the role of coastal seas playing in the global oceanic carbon cycle.

Supermedia User Interface for Scanning Probe Microscopy

当利用扫描隧道显微镜(SPM)作为一种纳米操作工具时,由于其缺乏实时的传感器信息反馈,而大大阻碍了它的广泛应用.利用超媒体人机交互接口可以解决这个问题.在纳米操作过程中,超媒体接口不但可以为操作者提供可实时更新的仿真操作场景,还可以通过力反馈手柄让操作者实时地感受到探针受到的三维纳米操作力.除此之外,操作者还可以通过该手柄直接控制探针的三维运动.最后在聚碳酸酯上进行了超媒体人机接口的纳米刻画实验.实验结果验证了该系统的有效性和效率.

Selenium-catalyzed reductive carbonylation of nitrobenzene with amines as coreagents to give unsymmetric phenylureas

The reductive carbonylation of nitrobenzene catalyzed by selenium to yield unsymmetric phenylureas has been studied. When secondary amines were used as coreagents, a single product, PhNHCONR2, was formed; when primary amines were chosen as coreagents, mixed products, including RNHCONHR, RNHCONHPh and PhNHCONHPh, were obtained. (C) 1999 Elsevier Science Ltd. All rights reserved.